Horsted Keynes (Kanes) rather than Milton Keynes (keens) - never got that
My bet is that the Sussex village has got the pronunciation right.....
"The village was originally known as Middeltone (11th century); then later as Middelton Kaynes or Caynes (13th century); Milton Keynes (15th century); and Milton alias Middelton Gaynes (17th century).[2] After the Norman invasion, the de Cahaines family held the manor from 1166 to the late 13th century as well as others in the country (Ashton Keynes, Somerford Keynes, and Horsted Keynes). During this time the village became known as Middleton de Keynes eventually shortening to Milton Keynes."
https://en.m.wikipedia.org/wiki/Keynes_family